Biotoxins and Bacteria

Before you harvest, please call 1-800-562-5632 or check the State’s daily bulletin to make sure the shellfish is safe to eat.

Biotoxins and bacteria not only affect our wildlife, but also the health of our people. Biotoxins are naturally occurring and are produced by microscopic algae that are concentrated in shellfish, and cannot be destroyed by cooking the shellfish. Eating these affected shellfish, even if properly cooked, can cause major health issues or even death. Toxins and pathogens that may affect shellfish in our U&A include:

PSP “Red Tide”: Also called “Red Tide,” PSP (Paralytic Shellfish Poison) is a biotoxin that cannot be destroyed through cooking, and can cause paralysis and asphyxiation. For more information at the Washington State Department of Health, click here.

DSP: DSP, or Diarrhetic Shellfish Poisoning, is a biotoxin. DSP cannot be destroyed by cooking and can cause nausea, vomiting, and diarrhea. For more information at the Washington State Department of Health, click here.

ASP: ASP, or Amnesic Shellfish Poisoning, is caused by Domoic Acid. Like other biotoxins, ASP cannot be destroyed through cooking. Severe cases of ASP can permanently damage short-term memory. For more information at the Washington State Department of Health, click here.

Fecal Matter & Pollutants: Fecal matter and pollutants frequently affect shellfish since shellfish are filter feeders and consume microscopic organic matter. Be sure to practice good hygiene and cook shellfish to a safe temperature (flesh of shrimp and crab should be cooked until opaque, and clams, mussels and oysters should open during cooking).

Throughout the year, our department sends bivavle samples to the Washington State Department of Health for testing. The DOH determines the toxicity levels in shellfish and closes beaches when necessary. In addition, the department conducts plankton tows to determine the presences of species known to produce biotoxins. This is an early warning system to help alert interested parties of the increased risk of the production of biotoxins by the algae.

DOH and the Tribes sample marine water to test for Fecal Coliform. Growing areas can also be closed due to rain events, sewer spills, or more non-point source events. Before you harvest please call 1-800-562-5632 or check the State’s daily bulletin to make sure the shellfish is safe to eat.

Vibrio Training

Vibrio is a naturally occurring bacteria found in saltwater and ingested by clams and oysters while they feed. There are many different species of Vibrio. The most prevalent in Puget Sound is Vibrio parahaemolyticus or Vp. In low doses, Vp poses no threat, however, when Vibrio is exposed to warm conditions, it multiplies rapidly and can cause vibriosis if ingested. Vibriosis is a serious intestinal disease with symptoms that can include diarrhea, adominal pain, nausea, vomiting, headache, fever, and chills.

The good news is that while contaminated seafood doesn’t look, smell, or taste any different, if some basic precautions are taken, vibriosis can be easily prevented.

Make sure to eat only properly chilled or well-cooked shellfish, especially in the summer months.

Do not consider shellfish to be fully cooked when the shells open. They need to reach a temperature of 145° F.

Other prevention tips include harvesting shellfish as soon as possible with the receding tide, keeping shellfish cold after harvesting, and limiting the sun exposure of harvested shellfish to less than an hour.